My Seatpin Is Stuck !



EasyDoesIt

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Apr 11, 2005
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Ok I've a Colnago Active with a Campag Chorus carbon seatpin and the seatpin is not stuck as such but very very very tight. I'm trying to lower the saddle a bit and after a lot of sweating i've managed to move it down 5 millimeters !!! Anyone have any suggestions that might help, at this stage i'm afraid to force it too much in case i break my saddle in the process !

Thanks in advance
 
EasyDoesIt said:
Ok I've a Colnago Active with a Campag Chorus carbon seatpin and the seatpin is not stuck as such but very very very tight. I'm trying to lower the saddle a bit and after a lot of sweating i've managed to move it down 5 millimeters !!! Anyone have any suggestions that might help, at this stage i'm afraid to force it too much in case i break my saddle in the process !

Thanks in advance
Give it a small spray of PB Blaster. "Don't bust your nuts, leave your wrench on the bench."
;)
 
Are you sure your seatpost is the correct size? It shouldn't be that difficult to move up or down if it is.

EasyDoesIt said:
Ok I've a Colnago Active with a Campag Chorus carbon seatpin and the seatpin is not stuck as such but very very very tight. I'm trying to lower the saddle a bit and after a lot of sweating i've managed to move it down 5 millimeters !!! Anyone have any suggestions that might help, at this stage i'm afraid to force it too much in case i break my saddle in the process !

Thanks in advance
 
carbonguru said:
Are you sure your seatpost is the correct size? It shouldn't be that difficult to move up or down if it is.
I misread the post. I equated "sweating" to corrosion, when you meant struggling... next move would be to try to remove the seatpost from the frame, then clean up the frame with scotch brite. I can't imagine a Colnago with the wrong size post, but I guess it's possible.
 
This may sound a bit barbaric, but it totally works. I learned it from a Shop I worked at when I was in school.

If you really can't get the seatpost out, turn the bike upside down. [This is really a 2 person fix, so grab a strong friend to help you out] Remove the bottle cage from the Seat Stay so that the cage bosses are bolt free and exposed. Get a lubricant, I use a brand called Marshalls, it works like WD-40 with out the greasy residue. Using the Plastic Flexy Straw these types of lube come with insert it into the Cage Boss and Spray a Generous Amount into the Cage Boss making sure that the lube is going south toward the saddle. Lift the frame off the ground anf have your buddy hold the downtube as tight as they can. Take a 2x4 that is cut to about 18 inches, place it on the setback of the post, take a rubber mallet and start wacking the **** out of 2x4 using a solid downward swing like you are pounding a post into the ground as the 2x4 sits fixed on the seatpost setback. [Make sure you keep constant contact with the 2x4 on the setback. No gap between the two] With every good wack the seatpost will come out an inch or so as you Buddy holds the frame off the ground and pulls up when you make contact with every swing. Keep wacking at it and eventually the Seatpost will be ejected.

Once the seatpost is out. Take a Dremel type tool and sand out the inside of your seatstay. Once again, make sure you have the correct size seapost. You may have a 32.4mm Seatpost when you only need a 31.6mm. I have seen this before on other Colnago Bikes. So check it out. Good luck! I wish I was there to help.


mrklein said:
I misread the post. I equated "sweating" to corrosion, when you meant struggling... next move would be to try to remove the seatpost from the frame, then clean up the frame with scotch brite. I can't imagine a Colnago with the wrong size post, but I guess it's possible.
 
carbonguru said:
This may sound a bit barbaric, but it totally works. I learned it from a Shop I worked at when I was in school.

If you really can't get the seatpost out, turn the bike upside down. [This is really a 2 person fix, so grab a strong friend to help you out] Remove the bottle cage from the Seat Stay so that the cage bosses are bolt free and exposed. Get a lubricant, I use a brand called Marshalls, it works like WD-40 with out the greasy residue. Using the Plastic Flext Straw these types of lube come with insert it into the Cage Boss and Spray a Generous Amount into the Cage Boss making sure that the lube is going south toward the saddle. Lift the frame off the ground anf have your buddy hold the downtube as tight as they can. Take a 2x4 that is cut to about 18 inches, place it on the setback of the post, take a rubber mallet and start wacking the **** out of 2x4 using a solid downward swing like you are pounding a post into the ground as the 2x4 sits fixed on the seatpost setback. [Make sure you keep constant contact with the 2x4 on the setback. No gap between the two] With every good wack the seatpost will come out an inch or so as you Buddy holds the frame off the ground and pulls up when you make contact with every swing. Keep wacking at it and eventually the Seatpost will be ejected.

Once the seatpost is out. Take a Dremel type tool and sand out the inside of your seatstay. Once again, make sure you have the correct size seapost. You may have a 32.4mm Seatpost when you only need a 31.6mm. I have seen this before on other Colnago Bikes. So check it out. Good luck! I wish I was there to help.
Before doing anything involving a Colnago and a hammer, I'd just take it to your LBS.:rolleyes:
 
Actually a Rubber Mallet. But I agree, the LBS would be a great place to start. ;)



mrklein said:
Before doing anything involving a Colnago and a hammer, I'd just take it to your LBS.:rolleyes:
 
carbonguru said:
This may sound a bit barbaric, but it totally works. I learned it from a Shop I worked at when I was in school.

If you really can't get the seatpost out, turn the bike upside down. [This is really a 2 person fix, so grab a strong friend to help you out] Remove the bottle cage from the Seat Stay so that the cage bosses are bolt free and exposed. Get a lubricant, I use a brand called Marshalls, it works like WD-40 with out the greasy residue. Using the Plastic Flexy Straw these types of lube come with insert it into the Cage Boss and Spray a Generous Amount into the Cage Boss making sure that the lube is going south toward the saddle. Lift the frame off the ground anf have your buddy hold the downtube as tight as they can. Take a 2x4 that is cut to about 18 inches, place it on the setback of the post, take a rubber mallet and start wacking the **** out of 2x4 using a solid downward swing like you are pounding a post into the ground as the 2x4 sits fixed on the seatpost setback. [Make sure you keep constant contact with the 2x4 on the setback. No gap between the two] With every good wack the seatpost will come out an inch or so as you Buddy holds the frame off the ground and pulls up when you make contact with every swing. Keep wacking at it and eventually the Seatpost will be ejected.

Once the seatpost is out. Take a Dremel type tool and sand out the inside of your seatstay. Once again, make sure you have the correct size seapost. You may have a 32.4mm Seatpost when you only need a 31.6mm. I have seen this before on other Colnago Bikes. So check it out. Good luck! I wish I was there to help.
I wish u were here to help too.

As far as i know the seat tube on the frame is 27 mm whereas the seatpost is 27.2mm, can't seem to get a 27 mm seatpost over here and didn't think it'd be that hard to move. I managed to get it to move nearly 10 mm down last night so will see how it goes like that, if i need it to go down more i'll use your advice, thanks for your help.
 
mrklein said:
Before doing anything involving a Colnago and a hammer, I'd just take it to your LBS.:rolleyes:
Hmmm good point about Colnagos and hammers or mallets !! Might be the LBS after all !
 
I suggest you pull out the seatpin first. I suspect you've created a trough on your carbon seatpin due to the sharp edge of the seat tube. Specially with a carbon seatpin, bike seat tubes should have the opening (edge) sanded to eliminate the sharp edge that could ruin CF seat posts. This is true not only with steel, ti or al frames but also with cf.
 
EasyDoesIt said:
I wish u were here to help too.

As far as i know the seat tube on the frame is 27 mm whereas the seatpost is 27.2mm, can't seem to get a 27 mm seatpost over here and didn't think it'd be that hard to move. I managed to get it to move nearly 10 mm down last night so will see how it goes like that, if i need it to go down more i'll use your advice, thanks for your help.
Well, this is APPARENTLY after-the-fact, but you can readily reduce a MANY older 27.2 seatpins to 27.0 since it appears that the blank used was the same for most sizes. This is not applicable with a most MODERN seatpins.

So, while this "reduction process" is not applicable for your carbon fiber seatpin, if you want to reduce an older, aluminum seatpin, you just need some emery cloth + time ... OR, a flat file + emery cloth + less time. Wrap some masking tape above the insertion level ... wrap the lower/exposed portion with the emery cloth, grab the emery cloth, turn the seatpost in the emery cloth cylinder you have created until the seatpost's diameter is reduced to ~27.0 ... OR, use a file to shave the area in question, first, and then polish it with the emery cloth until the seatpin is reduced to the proper diameter.

I have found with SOME steel older frames that the prior owner had over-tightened the collar AFTER inserting a seatpin that is the wrong size. IF the sides of the slot on the back of the seat tube are not parallel, then this is undoubtedly what may have happened since MOST steel Colnagos use 27.2 seatposts AND this may be the source of your difficulty.

IF SO, take a large (e.g., 12") screwdriver, and insert it into the slot in the back of the seat tube, and VERY gently nudge it so that the sides of the slot are parallel.
 
Thanks for all your help guys, as i said i got it a bit lower so will see how i get on, if not i think it'll be a trip to the LBS where i'm hoping they don't tell me my chorus carbon seatpost is damaged beyond repair :mad:
 
EasyDoesIt said:
Thanks for all your help guys, as i said i got it a bit lower so will see how i get on, if not i think it'll be a trip to the LBS where i'm hoping they don't tell me my chorus carbon seatpost is damaged beyond repair :mad:
If the post is where you want it, then I would leave it where it is for the NEXT SIX MONTHS ...

Although I don't generally bother, some people suggest that a seatpost should be removed periodically to prevent it from becoming one-with-the-bike.

So, leave it where it is, for now ...

Next Spring, see if you can remove it without twisting it back & forth ...

If you can, and if the frame is steel (which I presume it is based on the seatpost size), then tweak it back to 27.2 as I previously suggested.

Buy some JB WELD ... wash your post with soap & water ... rinse with some rubbing alcohol ... let dry ... apply some JB WELD in the groove you probably scoured into the post through your energetic insertion ... let cure. Sand smooth. Re-insert.

Spray with some clear coat before re-inserting if a glossy appearance is desired.
 
alfeng said:
If the post is where you want it, then I would leave it where it is for the NEXT SIX MONTHS ...

Although I don't generally bother, some people suggest that a seatpost should be removed periodically to prevent it from becoming one-with-the-bike.

So, leave it where it is, for now ...

Next Spring, see if you can remove it without twisting it back & forth ...

If you can, and if the frame is steel (which I presume it is based on the seatpost size), then tweak it back to 27.2 as I previously suggested.

Buy some JB WELD ... wash your post with soap & water ... rinse with some rubbing alcohol ... let dry ... apply some JB WELD in the groove you probably scoured into the post through your energetic insertion ... let cure. Sand smooth. Re-insert.

Spray with some clear coat before re-inserting if a glossy appearance is desired.
Yes seatpost is where i want it now, i was having problems with aches behind my knees so i lowered the saddle a bit and the aches have gone. But....the muscles just above my knees on my thighs seem to get tired quicker now is that because my legs have to used to the previous height and need time to adjust to this height ?

For the record, it's a Chorus Carbon Seatpin and the frame is a Colnago Active, part aluminum and carbon (the seat tube is aluminum).
 
One idea not mentioned is that, if you are talking about an aluminum seatpost in an aluminum frame, they will bond up if you do not periodically grease the post.
Take some of the cheap household ammonia (like you find in the grocery store) and tape some kind of sleeve around your seatpost, with electrical tape or something, so you can pour a tablespoon or so in around your seatpost.
Let it work down between the post and frame for a few minutes, and presto. The corrosive bond has been broken!
Always smear grease on it before reinstalling so it won't freeze again.
P.S. Don't imagine you want to grease a Carbon Fiber one --> just the metals
 
OK. I see you were talking about carbon fiber. Ignore my idea unless you have aluminum on aluminum.
Good luck to ya
 
EasyDoesIt said:
Yes seatpost is where i want it now, i was having problems with aches behind my knees so i lowered the saddle a bit and the aches have gone. But....the muscles just above my knees on my thighs seem to get tired quicker now is that because my legs have to used to the previous height and need time to adjust to this height ?
I had a similar problem when I changed my saddle height ... I originally attributed it to aging.

It took me a FEW YEARS to finally move my saddle rearward ... for me, it was like having new legs ...

So, if you have any fore-aft latitude in your saddle placement, try moving it back a bit.
 
alfeng said:
I had a similar problem when I changed my saddle height ... I originally attributed it to aging.

It took me a FEW YEARS to finally move my saddle rearward ... for me, it was like having new legs ...

So, if you have any fore-aft latitude in your saddle placement, try moving it back a bit.
Yes i tried moving the saddle backwards which made it worse in one leg but the other leg was perfect. So moved the saddle forwards and it's still there but not as bad, i wonder could it be that i'm not getting out enough cos i notice during the summer when i'm getting out a lot it doesn't be as bad !